The rubber-modified styrene-containing graft copolymer is widely used for electric/electronic products and office equipments because of its superior processability, physical properties, appearance and impact strength. And, the polyamide resin is used for machinery parts and electric/electronic materials because of its superior mechanical, thermal and chemical properties. Thus, a synergic effect of the two materials, that is, the moisture resistance and dimensional stability of the styrene-containing graft copolymer and superior mechanical, thermal and chemical properties of the polyamide resin, can be obtained when they are blended.
Because electric/electronic products and office equipments are exposed to a lot of heat, the resin used for them should have flame resistance.
It is known that use of a halogen based compound as flame retardant is the most effective way to male the rubber-modified styrene-containing graft copolymer flame resistant. Typical halogen based flame retardants are tetrabromobisphenol A, brominated epoxy, etc. It is also known that antimonial compounds improve flame resistance.
However, the halogen based compounds are known to generate gases that corrode the molds during processing and to generate gases toxic to human during combustion.
Particularly, bromine based compounds, which may generate environmental hormones such as dioxin and furan, are regulated by European countries. Also, the antimonial compounds are classified as toxic materials.